Turn cash, revenue, and expenses into the numbers every founder, VC, and emerging GP actually asks about: net monthly burn, how many months of runway you have, the exact zero-cash date, the month you reach breakeven, and Paul Graham's default-alive test — all from a month-by-month cash simulation that compounds revenue growth against cost growth. Pure client-side math; nothing leaves your browser.
"Net burn" is operating costs minus revenue. A negative net burn means you're already cash-flow positive this month. Growth rates compound monthly.
Net burn (this month) = operating costs − revenue. Positive = cash going out; negative = already cash-flow positive.
Simple runway = (cash + raise) ÷ net burn using only this month's figures (no growth). It's the back-of-envelope number; the simulation below is the honest one.
Growth-adjusted runway — a month-by-month simulation. Each month: cash −= (opex − revenue), then revenue ×= (1 + revGrowth) and opex ×= (1 + opexGrowth). Runway is the first month cash crosses below zero (interpolated within the month for the zero-cash date). Capped at 120 months — beyond that we report "10+ years / indefinite".
Months to breakeven — the first month where revenue ≥ opex (net burn ≤ 0) under the same compounding. If cost growth ≥ revenue growth and you start underwater, breakeven never arrives.
Default-alive vs default-dead (Paul Graham, 2015) — given current growth and spend, do you reach profitability before the cash runs out? Default-alive = breakeven happens while cash is still positive. Default-dead = you hit zero cash first and need another raise (or cuts) to survive. The test assumes no new hiring beyond your stated cost-growth rate.
What's intentionally omitted — seasonality, one-time inflows/outflows, changing growth rates over time, deferred revenue vs cash collection timing, and debt service. Use this as the fast read; a full 3-statement model handles the edge cases.
Educational financial-modeling tool — not investment, accounting, or tax advice. Cash-flow timing in a real business rarely compounds this smoothly; confirm against your actual bank balance and bookkeeping before any decision rides on it. All math runs in your browser; no inputs are sent to a server.